1. Field of the Invention
The present invention relates to a flywheel assembly in a vehicle power train. In particular, the invention relates to a flywheel assembly having a flexible input member, connectable to the crankshaft of an engine, and a damping mechanism supported on the flexible input member wherein power is transmitted to a main portion of the flywheel assembly via a combination viscous fluid and elastic damping means.
2. Description of Related Art
The damping out of torsional vibrations due to torque fluctuations transmitted from an internal combustion engine as the power-input source in a motor vehicle power train is an ongoing concern in the development of power train transmission devices. The problematic vibrations must be damped out in the transmission of power between the engine-power input side and the drive-shaft engaging output side (which can twist relative to the input side) of the power train ahead of the gearbox. For this purpose, elastic damping elements, typically coil springs, are conventionally introduced into the flywheel and/or clutch assemblies of the power train, to augment the smoothing out of torsional vibrations provided by the flywheel's inertial mass.
It is well known in the art to provide a viscous damping means. For example, a viscous damping mechanism may be provided within a power train flywheel assembly, wherein chief components of the flywheel assembly are elastically connected in the direction of power transmission rotation by coil torsion springs.
Flexural vibrations, transmitted from the crankshaft of the engine, are not, however, effectively damped by the means just described. Accordingly, it has been conceived to employ a flexible plate or the like for connecting the power train flywheel assembly, nonetheless incorporating the torsional vibration damping mechanism, with the engine crankshaft in order to damp out and absorb such flexural vibrations. Design problems herein include complicating overall construction by the addition of the flexible plate, increasing the axial dimension of the power train section and making extra parts necessary.